Moss E.H.R.,Swedish University of Agricultural Sciences |
Hipkiss T.,Swedish University of Agricultural Sciences |
Oskarsson I.,Swedish Golden Eagle Society |
Hger A.,Swedish Golden Eagle Society |
And 5 more authors.
Journal of Raptor Research | Year: 2012
The reproductive performance of the Golden Eagle (Aquila chrysaetos) was studied across 1055 territories from 19802009, in relation to indices of their primary prey (grouse Tetraonidae species and mountain hare Lepus timidus) and cyclic vole (Myodes and Microtus) populations in northern Sweden's boreal forest. Reproductive performance was measured as the number of live nestlings ≥4 wk old (hereafter termed nestlings) per breeding attempt, the percentage of territories with nestlings, and as an annual population production index. Despite the large interannual variation in the reproductive performance of the Golden Eagle, autocorrelations did not reveal any short-term periodicity as had been predicted in the literature. Using multiple regression, we found that the index of annual population production and the percentage of territories with nestlings were significantly related to the concurrent indices of their primary prey populations. Further, the index of annual population production was also significantly related to the pooled abundance of voles (bank voles Myodes glareolus and field voles Microtus agrestis) in the previous autumn. In all, 28 of the total variation in the index of annual population production was explained by the prey population variables. © 2012 The Raptor Research Foundation, Inc.